Left Temporal Lobe Resection Linked to Naming Decline in Refractory Epilepsy

Patients with refractory epilepsy who undergo left temporal lobe resection (TLR) should be made aware of the risk of a decline in word-finding ability or naming, in addition to memory decline, according to data published in Neurology.¹

While patients who undergo temporal lobe resection are typically counseled regarding the risk of postoperative memory impairment, many patients also exhibit language impairments, which can significantly affect quality of life.² Naming decline occurs in 25 to 60% of adults who undergo TLR^3,4; however, little is known about the factors that may put patients at risk for naming decline.

In this study, the researchers sought to examine the frequency and severity of naming difficulties, as they relate to the side and site of lobe resection. The retrospective study used data from a neuropsychological registry consisting of patients with refractory epilepsy aged 16 and older who underwent epilepsy surgery at the Cleveland Clinic between 1986 and 2015.

Ultimately, 875 patients (454 left/421 right; 763 temporal/87 frontal/25 posterior quadrant; mean age 35 years) met all inclusion criteria. All participants completed the Boston Naming Test prior to surgery. Those who underwent right-sided resections rarely experienced naming decline (5% overall; 90% confidence interval [CI] ± 2%), compared with 41% of patients (CI ± 5%) in the left temporal resection group and 10 to 12% in the other left-sided resection groups (CI ± 10-19%). Seventeen percent of patients who underwent left TLR experienced significant declines in naming (>11 points on a 60-point scale); those patients tended to have a later age at seizure onset, older age at surgery, and higher baseline naming ability. When applied to the cohort, the factors accurately predicted naming decline in 68% of patients as well as severity of decline in those who underwent left TLR.

“Our results suggest that patients should also be counseled regarding the risk for decline in naming ability following surgery, particularly given that there are a subset of patients who demonstrate catastrophic decline possibly reflecting a broader aphasic syndrome,” the authors noted. “Therefore, development of risk models to predict naming outcome, akin to those that have been developed for memory, are needed to improve preoperative counseling for patients considering epilepsy surgery.”

The authors have provided a decision tree to assist clinicians in counseling patients who are candidates for left TLR on the risk of naming decline.

Disclosures: Dr Najm reports that he is a member of the Sunovion Speakers Bureau.

References

1. Busch RM, Floden DP, Prayson B, et al. Estimating risk of word-finding problems in adults undergoing epilepsy surgery. Neurology. 206 Nov 4; doi:10.1212/WNL.0000000000003378 [Epub ahead of print]
2. Perrine K, Hermann BP, Meador KJ, et al. The relationship of neuropsychological functioning to quality of life in epilepsy. Arch Neurol. 1995;52:997–1003.
3. Ives-Deliperi VL, Butler JT. Naming outcomes after temporal lobectomy in epilepsy patients: a systematic review of the literature. Epilepsy Behav. 2012;24:194–198.
4. Sherman EM, Wiebe S, Fay-McClymont TB, et al. Neuropsychological outcomes after epilepsy surgery: systematic review and pooled estimates. Epilepsia. 2011;52:857–869.